The contractor's laboratory will be used chiefly for long-term treatments, holding, and observation of animals in carcinogenesis investigations emphasizing life-time tumor induction in rodents and related activities. The animal facilities will have mice (including athymic nude mice), rats, Syrian Hamsters, guinea pigs, and rabbits. Chemical carcinogens will be administered to animals by skin painting, gavage, parenteral injection, or intratracheal instillation. Further services required include: refrigeration facilities for animal diets, tissue preparation, etc., operating at 4 degrees C, -20 degrees C, -70 degrees C, and liquid nitrogen temperatures; and nude mouse maintenance facility.